Impact of Specific Epidermal Growth Factor Receptor (EGFR) Mutations and Clinical Characteristics on Outcomes After Treatment With EGFR Tyrosine Kinase Inhibitors Versus Chemotherapy in EGFR-Mutant Lung Cancer: A Meta-Analysis

Characteristics and overall survival of EGFR mutation-positive non-small cell lung cancer treated with EGFR tyrosine kinase inhibitors: a retrospective analysis for 1660 Japanese patients

Background

The Japan Guidelines of Lung Cancer Therapy recommend epidermal growth factor receptor-tyrosine kinase inhibitors as a first-line therapy for advanced/recurrent non-small cell lung cancer patients with epidermal growth factor receptor mutation. Although survival periods in recent reports of epidermal growth factor receptor-tyrosine kinase inhibitor treatment have been getting longer, the reasons why are unclear. We investigated the survival, prognostic factors and real-world treatment of non-small cell lung cancer patients with epidermal growth factor receptor mutation in clinical practice.

Methods

Non-small cell lung cancer patients (n = 1660) who started first-line treatment from January 2008 to December 2012 were enrolled. Patients were diagnosed with epidermal growth factor receptor mutation-positive advanced/recurrent non-small cell lung cancer by histology or cytology samples. The primary objective was to estimate overall survival. The secondary objectives were to determine prognostic factors, real-world treatment patterns and efficacy of gefitinib treatment. We calculated the treatment exposure rate for each treatment category using the following formula: exposure rate = person-years for the treatment category/total person-years × 100.

Results

The median overall survival was 30.8 months. Sex, age, histology, epidermal growth factor receptor mutation type, clinical stage and performance status affected overall survival. The exposure rates for all epidermal growth factor receptor-tyrosine kinase inhibitors, gefitinib and platinum-doublet chemotherapy were 62.1, 46.4 and 8.5% respectively. Overall 56.1% of patients were administered gefitinib as first-line therapy, and 39.0% were treated with ≥2 epidermal growth factor receptor-tyrosine kinase inhibitor regimens. The median progression-free survival in the first-line gefitinib group was 11.4 months. Factors affecting prognosis were sex, histology, clinical stage and performance status.

Conclusion

Epidermal growth factor receptor-tyrosine kinase inhibitors, especially gefitinib, are major components of the treatment regimens for epidermal growth factor receptor mutation-positive non-small cell lung cancer. Switching and re-challenging with epidermal growth factor receptor-tyrosine kinase inhibitors were also practiced in Japan.

Second- and third-generation ALK inhibitors for non-small cell lung cancer

Crizotinib as the first-generation ALK inhibitor has shown significant activity in ALK-mutated non-small cell lung cancer (NSCLC). Second- and third-generation ALK inhibitors are entering clinical applications for ALK+ NSCLC. In addition, a third-generation ALK inhibitor, lorlatinib (PF-06463922), was reported to resensitize NSCLC to crizotinib. This review provided a summary of clinical development of alectinib, ceritinib, brigatinib (AP26113), and lorlatinib.

Afatinib in the first-line treatment of epidermal-growth-factor-receptor mutation-positive non-small cell lung cancer: a review of the clinical evidence

First-line afatinib significantly improved progression-free survival, patient-reported outcomes, and quality of life compared with chemotherapy regimens in patients with advanced epidermal-growth-factor-receptor (EGFR) mutation-positive non-small cell lung cancer, based on results of the LUX-Lung 3 and LUX-Lung 6 trials. When the analysis of these trials was restricted to patients with common EGFR mutations only (exon 19 deletions and L858R), the advantage over chemotherapy was even more pronounced. A significant overall survival advantage was firstly demonstrated versus chemotherapy in patients with non-small cell lung cancer-harboring EGFR exon 19 deletion (del19) mutations. First-line afatinib was also effective in patients with certain uncommon EGFR mutation and patients with central nervous system metastasis. So far, these data are not sufficient to conclude that afatinib is better than first-generation EGFR inhibitors. In addition, the toxicity profile of afatinib was somewhat worse than that observed with either erlotinib or gefitinib. In the absence of direct comparisons, for each patient the choice among the available EGFR inhibitors should take into account all the clinically relevant endpoints, including disease control, survival prolongation, tolerability, and quality of life.

Whacking a mole-cule: clinical activity and mechanisms of resistance to third generation EGFR inhibitors in EGFR mutated lung cancers with EGFR-T790M

Epidermal growth factor receptor (EGFR) mutations, especially EGFR-exon 19 deletions and EGFR-L858R, are the most frequent actionable genomic events in lung adenocarcinomas. Tumors arise due to constitutively activated EGFR signaling and are susceptible to EGFR tyrosine kinase inhibitors (TKIs). First generation EGFR TKIs (gefitinib and erlotinib) and the second generation EGFR TKI afatinib are approved worldwide. Although targeted therapies against EGFR mutants induce dramatic initial responses, acquired resistance (through multiple biological mechanisms) to erlotinib, gefitinib and afatinib emerges within the first 1-2 years of continued monotherapy. EGFR-T790M accounts for more than half of acquired resistance to first or second generation EGFR TKIs by modifying ATP affinity and drug binding kinetics. Two new studies have shown that two covalent pyrimidine inhibitors-AZD9291 and rociletinib of EGFR-T790M (i.e., third generation EGFR TKIs) shown remarkable clinical activity in patients with acquired resistance to erlotinib, gefitinib and afatinib when the tumor carries EGFR-T790M in conjunction with an activating mutation. However, and regrettably, acquired resistance to these third generation EGFR TKIs has already been reported in preclinical models and clinical specimens; such as a tertiary mutation at EGFR-C797S that prevents covalent binding of EGFR TKIs. The experience with sequential EGFR TKI monotherapy highlights tumor heterogeneity and adaptability (i.e., relentless game of whack-a-mole played between TKIs and cancer), and will help shape future clinical development of novel combinatory approaches to manage EGFR mutated lung adenocarcinomas.

Low Prognostic Nutritional Index Correlates with Worse Survival in Patients with Advanced NSCLC following EGFR-TKIs

Objective

This study was designed to demonstrate the prognostic value of prognostic nutritional index (PNI), a reflection systemic immunonutritional status, on the long-term survival of patients taking epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs).

Methods

In this retrospective study, eligible advanced NSCLC patients with sensitive EGFR mutations (exon 19 deletion or L858R in exon 21) were included to investigate the correlation between the PNI and overall survival (OS). The PNI was calculated as 10 x serum albumin value (g/dl) + 0.005 x peripheral lymphocyte count (per mm³). The prognostic significance of PNI and other clinicopathologic factors was identified by univariate and multivariate analysis.

Results

Finally, 144 patients met the inclusion criteria. The optimal cut-off value of PNI for survival stratification was 48.78. Compared with high PNI group (n = 81), low PNI (n = 63) was significantly associated with elevated C-reactive protein (CRP) level and non-response to TKIs. Overall survival was superior in the high PNI group (HR, 0.44, p = 0.004), especially for patient with L858R (HR, 0.37, p = 0.009) rather than 19 deletion (HR, 0.69, p = 0.401). The independent prognostic value of PNI was validated by multivariate analysis.

Conclusion

This pilot investigation demonstrated that low prognostic nutritional index correlates with worse survival for patients with advanced NSCLC and taking EGFR-TKIs. The assessment of a convenient index, known as PNI, worth attention in routine clinical practice for patients following EGFR-TKIs treatment.

The Risk of Neutropenia and Leukopenia in Advanced Non-Small Cell Lung Cancer Patients Treated With Erlotinib: A Prisma-Compliant Systematic Review and Meta-Analysis

Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are a critical member of systemic therapy for advanced non-small-cell lung cancer (NSCLC). Erlotinib is the first-generation EGFR-TKIs, the National Comprehensive Cancer Network (NCCN) guidelines recommend it as a first-line agent in patients with sensitizing EGFR mutations. However, the safety of erlotinib plus chemotherapy (CT) or erlotinib alone for advanced NSCLC remains controversial. We carried out a systematic meta-analysis to determine the overall risk of neutropenia and leukopenia associated with erlotinib. PubMed, EMBASE, CBM, CNKI, WanFang database, The Cochrane library, Web of Science, as well as abstracts presented at ASCO conferences and ClinicalTrials.gov were searched to identify relevant studies. RR with 95% CIs for neutropenia and leukopenia were all extracted. The random-effects model was used to calculate pooled RRs and 95% CIs. Power calculation was performed using macro embedded in SAS software after all syntheses were conducted. We identified 12 eligible studies involving 3932 patients. Erlotinib plus CT or alone relative to CT is associated with significantly decreased risks of neutropenia and leukopenia in patients with advanced NSCLC (RR, 0.38; 95% CI, 0.21-0.71; P = 0.00; incidence: 9.9 vs. 35.2%) and (RR, 0.32; 95% CI, 0.11-0.93; P = 0.04; incidence: 3.5 vs. 11.6%), respectively. The subgroup analysis by erlotinib with or without CT showed that erlotinib combine with CT have no significance decrease the relative risks of neutropenia or leukopenia (RR, 0.98; 95% CI, 0.78-1.23; P = 0.87; incidence: 26.2 vs. 30.5%) and (RR, 0.81; 95% CI, 0.34-1.95; P = 0.64; incidence: 6.5 vs. 9.3%), respectively. However, erlotinib alone could decrease incidence of neutropenia (RR, 0.14; 95% CI, 0.07-0.27; P = 0.00; incidence: 3.7 vs. 40.8%) or leukopenia (RR, 0.07; 95% CI, 0.01-0.45; P = 0.01; incidence: 0.8 vs. 15.7%). The power analysis suggests that a power of 61.31% was determined to detect an RR of 0.38 for neutropenia, and 78.03% for an RR of 0.32 for leukopenia. The present meta-analysis suggested that erlotinib could decrease the incidence of neutropenia and leukopenia in patients with advanced NSCLC undergoing erlotinib regardless of whether combined with CT or not. The subgroup analysis revealed that erlotinib combine with CT did not affect the incidence; however, erlotinib alone could significantly decrease the incidence of neutropenia and leukopenia compared with CT alone.

Anaplastic Lymphoma Kinase Variants and the Percentage of ALK-Positive Tumor Cells and the Efficacy of Crizotinib in Advanced NSCLC

BACKGROUND

Anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer patients exhibited heterogeneous magnitude of response and duration time to criztotinib treatment. This study explored ALK variants and the percentage of ALK-positive cells using fluorescent in situ hybridization (FISH) on clinical efficacy of crizotinib.

PATIENTS AND METHODS

A total of 120 patients with ALK rearrangement who were treated with criztotinib were enrolled. ALK variants were clarified in 61 patients, and ALK percentages were evaluated using FISH in 114 ALK-positive patients. Retrospectively, objective response rate, and progression-free survival (PFS) were evaluated.

RESULTS

A total of 61 patients with specific ALK variants were divided into 3 subgroups, echinoderm microtubule-associated protein like 4 (EML4)-ALK variant 1 (n = 22), EML4-ALK variant 3a/b (n = 18), and other ALK variants (n = 21). Median PFS in the 3 subgroups was 11.0 months (95% confidence interval [CI], 5.5-16.5), 10.9 months (95% CI, 5.9-15.8), 7.4 months (95% CI, 3.2-11.6), respectively, and no significant difference (P = .795) existed among them. The percentage of ALK-positive cells in FISH analysis was weakly correlated with PFS (rs = 0.235; P = .015). Additionally, it was also weakly correlated with best response to crizotinib (rs = 0.288; P = .003). Overall, there were 45, 49, and 26 patients receiving first, second, and third or further-line crizotinib, respectively. Median PFS in the first-line setting (10.5 months; 95% CI, 8.6-12.4) was significantly longer than that in the second-line setting (8.3 months; 95% CI, 4.7-12.0; P = .020).

CONCLUSION

Anaplastic lymphoma kinase variants might have no correlation with clinical response to crizotinib. The percentage of ALK-positive cells might correlate with the extent of benefit from crizotinib treatment.